Core-shell behavior and exchange bias of Fe-doped CuO nanoparticles

Autor(es)

Oliveira, Aline Alves ^[1] ; Valerio-Cuadros, Marlon Ivan ^[1] ; de Brito, Alex Soares ^[1] ; Tupan, Lilian Felipe Silva ^[1] ; Ivashita, Flavio Francisco ^[1] ; Geshev, Julian ^[2] ; Paesano, Jr., Andrea ^[1]

Afiliação do(s) autor(es)

^[1] Univ Estadual Maringa, Dept Fis, Ave Colombo 5790 Jardim Univ, BR-87020900 Maringa, PR - Brazil

^[2] Univ Fed Rio Grande do Sul, Inst Fis, BR-91501970 Porto Alegre, RS - Brazil

• Tipo de documento: Artigo Científico
• Fonte: AIP ADVANCES; v. 10, n. 6 JUN 1 2020.
• Citações Web of Science: 0

Resumo

Cu1-xFexO nanoparticles were prepared using a freeze-drying process followed by heat treatment. The particles were then characterized using Mossbauer spectroscopy and magnetization techniques. The results revealed complex magnetic behavior, which can be attributed to the presence of two different magnetic regions: the particle core, which has antiferromagnetic fluctuations, and the particle shell, where uncompensated spins are responsible for their superparamagnetic characteristics. At low temperatures, the moments freeze, revealing a ferromagnetic order for the shells and a dipolar magnetic interaction among the nanoparticles. In addition, an exchange-bias field revealed magnetic interactions between the core and the shell of the nanoparticles. The ferromagnetism observed in this system suggests that antiferromagnetic oxide matrices can be used for diluted magnetic semiconductor applications, if suitably doped. (AU)

• Processo FAPESP: 09/54082-2 - EMU: projeto para aquisição de um magnetômetro de amostra vibrante que utiliza como sensor um dispositivo supercondutor de interferência quântica acoplado (Squid-VSM) com circuito fechado de criogenia
• Beneficiário: Ernesto Chaves Pereira de Souza
• Modalidade de apoio: Auxílio à Pesquisa - Programa Equipamentos Multiusuários